Foot and shoe length differ because a gap between the end of the longest toe on the foot and the inside of the cap of the shoe differ. This gap difference varies between 20mm and 8.5mm depending on how the shoe was made and the method of measurement.

20mm = .79 inches (just over 3/4 inch), 8.5mm = .33 inches (1/3 inch)

The average difference between foot length and shoe length should be aproximatly 13 millimeters (1/2 inch). 13 millimeters is equal to about one and a half shoe sizes. This scale uses 13 mm as the standard gap.

You will typically need an athlitic shoe 1/2 to a full size larger than a dress/business shoe.

Toe Length: The length of a foot, from heel to toe, should be about 1.4 times the length of the same foot from heel to the ball of the foot (center of the large joint behind the big toe). If this ratio is less than 1.35 then the next half shoe size size up may fit better.

Shoe Width Info:

Shoe width is set at 3/8 (.375) of the length of the shoe to determine a “D” size width, so the width of a shoe will always change in relationship to the length of the shoe.

Shoe width designations change by 5mm, .19 inches (3/16 inch) for each change in designation, therefore a size B would be 10mm smaller in width
than a size D, and a EE would be 10mm larger than a size D.

Most shoe makers in the UK use a different width designator than the US, with F being the medium size designator in the UK, rather than D which is the medium designator in the US.

Scale Accuracy:

This scale is offered as a reference only, because each shoe maker uses their own set of custom lasts (a “Last” is a shoe form on which a shoe is built) which vary from maker to maker, and style to style.

There is also a deviation between US and UK sizes that varies from a half to a full size difference.

Ready to Wear (RTW) is a term used to describe shoes manufactured for the general public, using a (somewhat) standardized measurement method, and produced in quantity. Over 90% of the shoes sold in the world are RTW.

Contrast this with the fact that every human foot in the world is shaped differently than the next, even the feet of an individual person differ slightly in shape from each other.

Typically the foot opposite the dominate hand will be slightly longer, and the other foot will be slightly thicker.

The general rule is to buy your shoes to fit the length of the longer foot, and the width of the thicker foot. This almost guarantees you will never find a perfect fitting pair of shoes unless you go bespoke (custom made).

The differences in size and shape between a person’s feet vary per person, with some people having feet of almost exactly the same size, to people with a difference of half a size or more.

So how do you make your shoes fit your feet the best they can?

Well, part of this issue is addressed by the flexible nature of feet, along with the malleable nature of the leather upper to form to your foot.

Unfortunately, the shape imbedded into the sole (insole/outsole) of the shoe to fit the bottom of the foot is not so forgiving. A shoe is designed to fit a foot from the heel of the foot to the ball of the foot (as I have mentioned in other articles).

When stepping forward your heel strikes the ground first, driving the heel of your foot into the heel cup of the shoe (above the shoe heel), and against the internal heel counter (at the back of the shoe). The heel cup sits lower in the shoe than the arch to accommodate the shape of the heel bone, just as the heel counter of the shoe curves around the back of the foot to accommodate the shape of the heel bone. This is very important to the fit of the shoe.

The part of the sole where the ball of the foot rests also has a curve to it and sits lower than the arch to accommodate the ball of the foot striking the ground.

When walking, the foot first gets driven into the heel cup, then as you step forward the foot slides forward (ever so slightly – if the shoe fits properly) to place the ball of the foot into the curvature designed for it.

If the shoe is too long the foot will have to slide farther to allow the ball of the foot to press down where it needs to. This will also cause the heel of the foot to come too far out of the heel cup of the shoe and rub against the heel counter (causing blisters, and possibly other issues).

If a shoe is too small the ball of the foot will be pushed forward into the toe of the shoe (which is not only uncomfortable, but can cause blisters and other issues). As a side note: this is where women get most of their foot problems from; the shoes are either too small for their feet, or poorly constructed in the toe for proper movement (sometimes by design).

The more common problem in men’s shoes is that they are slightly too big (on one foot, or both), which can be addressed (to some degree) with inserts and pads.

The most common insert is the removable rubber insole that you can find at most department stores. This is also probably one of the least effective ways of making a shoe fit properly.

The reason that a removable rubber insole is a bad choice for improving shoe fit is because it pushes to foot slightly up and out of the heel cup, and presses the instep and toes into the tongue and/or vamp of the shoe.

While pressing the instep into the tongue or vamp may be a desired effect to make the shoe feel tighter, it caused the heel of the foot to rest higher against the heel counter which can again cause blisters and other issues, as well as impacting the proper motion of the foot.

If you feel you must get a removable rubber insole, try to get the thinnest one you can that has the desired effect.

Another pad that is used on shoes that slip too much in the heel (typically because the shoe is too long) is a heel pad that sticks to the inside of the back of the shoe over the internal heel counter and curves to match the horizontal curvature of the back of the shoe. While this solution does not necessarily push the foot up, it does push the heel of the foot forward, and therefore pushes it out of the heel cup. This pad also has the potential to cause damage to the Achilles tendon over time.

One of the better solutions for a shoe that is too big is to use a tongue pad. A tongue pad is a triangle shaped cotton pad with adhesive on one side to stick to the underside of the tongue (or vamp) of the shoe to add more girth inside the shoe.

This helps the fit of the shoe because it pushes the foot down into the insole and the heel cup. The downside is that your socks won’t slide quite as well into your shoe with the cotton pad there, and it takes a while to remove the adhesive residue if you remove the pad.

A tongue pad will not solve the problem of a shoe being too long, but it creates a better fit than the other solutions.

In order to understand what makes a shoe fit the way that it does, you have to have some understanding of how the shoe is made.
Shoes are constructed on an object called a “Last”. The Last is a form made of wood or plastic that the leather of the shoe is wrapped over to create the shape of the shoe upper.

Each manufacturer of shoes has their own set of lasts, in each size and last design that they make. So not only can shoe fit vary from brand to brand, in the same size, but it can vary within a brand depending on which Last design was used for a given style of shoe. Manufacturers also update their Lasts from time to time, so a newer version of the same style shoe may fit differently than a previous one.

It is also very important to note that Lasts are measured in a multitude of ways, not just length and width like a foot.

In reality a shoe is never made to fit a foot from heel to toe, it is made to fit your foot from heel to ball (at the base of your large toe). A formula is used to determine the minimum length of the shoe past that point, but this allows the designer to define different toe shapes without worrying about shoe length.

Next time you are in a shoe store or shoe department, look at the Brannock device used to measure your foot. There is a little piece that slides up next to the ball of your foot that actually tells your shoe size, not the length of your foot (which is also measured by a Brannock device).

Another interesting thing to note is that the width of a shoe is not determined by the width of your foot at the ball of your feet, it is measured in the girth of the Last in the area of the instep and ball of the foot.

The width of your foot varies constantly, unless it is at rest. And, it can form to different shapes, to some degree. This allows for different Lasts to have different widths at the instep/ ball, while still maintaining the same width sizing. As long as the girth is the same (narrower, but with a higher instep, for example) the width measurement is the same.

The phrase “fits like a glove” is not applicable here. There are only 5 sizes of gloves (XS, S, M, L, XL), but there are about 20 standard shoe sizes, and it is still hard to get a perfect fit (without going bespoke). The best you can hope for is a comfortable fit.

This is why it is so important to try shoes on before you buy them, rather than buying online. However, many online shoe stores have great return policies just for this reason.
If you find a shoe that fits you very well, try to find out the manufacturers Last model. This will allow you to buy shoes other shoes built on that Last. You can also look for a similar Last shape from another manufacturer to get a good fit. Most of the better quality shoe manufacturers either publish, or can tell you, which Last a given shoe model was built on.